I have new in box, Progress Mustang GT lowering springs. $175 firm. In Costa Mesa. Check out the pics. I have them because I have just traded in my 06 and hadn't installed them.
Here's the link for Progress. I was really looking forward to installing these too. Features -Front drop: 1.3" --- Rear drop: 1.8" -Front rate: 240 lbs/in --- Rear rate: 210 lbs/in -Limited lifetime warranty! -All spring kits are powdercoated metallic gray. The Progress Group - Sport Springs Ford Mustang GT 05-09 Ford Mustang GT Sport springs